Spectral condition for the existence of a chorded cycle

Abstract

A chord of a cycle $C$ is an edge joining two non-consecutive vertices of $C$. A cycle $C$ in a graph $G$ is chorded if the vertex set of $C$ induces at least one chord. In this paper, we prove that if $G$ is a graph with order $n\geq 6$ and $\rho(G)\geq \rho(K_{2,n-2})$, then $G$ contains a chorded cycle unless $G\cong K_{2,n-2}$. This gives one answer to a question posed by Gould [Results and problems on chorded cycles: A survey, Graphs Combin. 38 (2022) 189].